Tag Archives: water

A few years ago I wrote a book called “The Pumpkin Project.” It was based on some of the experiments I’d used in my classes to explore botany. At the time I was also doing science projects on my website. One summer those projects were about exploring water.

As I finished “The Pumpkin Project,” I planned to do another science book called “The Water Project.” After all, I had the experiments. The book didn’t get done.

I enjoy science. Finding out about how things work is interesting. At least, it’s interesting if you do the experiments instead of just reading about them. Too many schools and teachers have students read the text and answer the questions with no lab work.

Water is getting a lot of attention lately. A person can live on water alone for about a month. Without water survival shrinks to a week. For many people around the world, getting enough clean water is a daily challenge.

Do you know what this is and what it does? Do you know how it works? That will be in “The City Water Project.”

Water is so necessary, yet we in the United States rarely give it a thought. It is supposed to be there whenever we want it.

How much do you really know about water? Where does your water come from? What happens to that water before it arrives in your house? What happens to it after it leaves your house?

“The City Water Project” is taking form. The investigations allow young people to do labs exploring water, what it is and how it works. The activities can be fun. The project will be challenging.

As in “Goat Games” and “The Pumpkin Project,” there will be pencil puzzles to work. These too will aid in exploring water. My biggest challenge will be not making the puzzles too difficult. But you might like a challenge.

“The City Water Project” will be lots of fun over a summer. After all, what fun is exploring water if you can’t get wet?

People, gardens and livestock require water. Cities and towns generally have water departments and pipes taking water to houses and businesses. Some rural areas join together to form water districts to supply water to their members.

Most rural areas leave water supply up to the land owners. There are generally four sources in the Ozarks: drilled well; springs; rain; and surface sources such as dug wells, ponds and streams.

Ozark Water Facts

I love to garden. It’s a great way to take out frustration pulling those persistent weeds. It’s relaxing to dig in the dirt. Those little sprouts are exciting to see. Fresh, home grown food, especially food you grow yourself, prepared for dinner is so satisfying on several levels.

Floods or, more accurately, high water events are not uncommon in the Ozarks. They are usually short-lived but destructive. The bedrock of the Ozarks accounts for this.

This bit of exposed bluff rock has some cavities in it but they don’t open into any caves we know of. There is no water coming out from this rock but it stays moist from the creek just below. The rock is pitted with cracks both horizontally and vertically.

Lesson 1: Missouri has Lots of Caves and Rocks

The Ozark Plateau is a Karst formation. This is a huge block of limestone riddled with holes formed by acidic rainwater seeping through the rock and dissolving some of it. Such an area, and there are other Karst areas around the world, are known for caves, sinking streams, sinkholes and springs.

A common belief is that water seeping through soil is cleaned of much of the debris in it. This is not true in a Karst area. Debris falls through or is dumped into sinkholes and sits for decades with water flowing by. A stream can carry debris with it as it flows down through a crevice and disappears. The debris may or may not arrive at the spring where the water reappears.

Parts of the Ozarks have a granite bedrock. Everywhere the rocks break into small pieces. The soil seems to grow a new crop of rocks every year. Rarely is the soil more than inches deep.

My garden soil has a lot of gravel in it. This is annoying when I try to rake a seed bed smooth. But big rains rarely make a mess of my garden as the water drains through quickly.

Other people I’ve talked to have more clay and their gardens can stay muddy for weeks. Still, the vegetables usually survive or even thrive with the moisture.

Drought is different. Drought creeps up as day follows day with no rain. The garden starts drying up. The plants shrivel. The weeds curl their leaves and droop. Only water can help them.

Rain barrels under a drain spout or eave overhang fill quickly. Mosquitoes can be a problem. I have an aquarium fish net and sweep them up every day or so to keep the larva from hatching into adults. The larva dry out quickly when tossed on the ground.

Lesson 2: Supplying Water to the Homestead

Filling jugs in town is possible but a real nuisance. There is never enough. Buying bottled water is expensive. The best way is to have water on site.

Rain is one source of water. In the Ozarks rain is a feast or famine proposition. That is where rain barrels, ponds and streams help. Some old houses still have cisterns under them filled from rain funneled down from the roof.

I use rain barrels for watering my garden. There are two roofs overhanging the garden and I place the barrels there to catch the run off from March to November. Plastic barrels do not do well filled with ice.

During long dry spells, I supplement the rain barrels by refilling them with water pumped from a nearby creek. This method works fine during short dry spells. The creek disappears under its gravel bed in droughts. Ponds dry up. Even springs can stop flowing.

All of these are lumped under surface water. This means the water can pick up all kinds of things from debris to manure to chemicals from the surfaces it flows over. Garden plants and soil filter out much of this. Using these for drinking water without filtration is risky.

A neighbor uses a spring for house water. The spring has a fairly large flow but does fluctuate according to the rainfall or lack of it. The amount of mud and debris flowing out of the spring increases in wet weather. The water must be filtered carefully at all times as a spring is basically surface water and can have any number of pollutants in it.

Another is a dug well. This goes down into the water table. The water in the well is surface water and the level will rise in wet conditions and fall in dry conditions. Heavy manure or fertilizer applications will taint the water quickly.

I have a dug well and do use it for livestock water buckets. The water temperature stays about the same all year so the goats appreciate relatively warmer or cooler water depending on the season. The well is above my garden so compost doesn’t affect it. We have no close neighbors above the well so the water stays palatable to the goats.

This water may be used to cool off in the summer but is not used for drinking water. Lots of creatures call the well home even though the top is covered. I occasionally pump up amphipods, little white shrimp like creatures.

The other option is a drilled well. Having one put in is expensive but the well rarely goes dry even during a drought. The well requires a pump, pipes and pressure tank.

A well bucket can be used in a drilled well. The bucket is dropped down into the water to fill then pulled up using a crank. This is a lot of work for a small amount of water, about two gallons. I’ve done this before and did not enjoy it.

Drilled wells with good casings to keep surface water out of the well are the most reliable source. The amount of water flowing into the well determines how much water can be pumped out before there is no water to pump. The water level will gradually rise again but doing this is hard on the pump and can ruin it.

The original dug well has a cement slab over it with a small opening. We covered this opening to keep chickens etc. from falling in and put in the hand pump. The pump must be easily removable to change the leathers or flexible ends on the pump pipe that control the water flow out while you are trying to pump the water up the pipe.

Lesson 3: Considering Water

How much water you need depends on how the water will be used. Gardens and livestock take lots of water. Washing machines, dishwashers and long showers take a lot of water.

The garden can be left to die in mid summer when rain is scarce. Clothes can go to the laundromat. Showers can be timed. Water is still an issue.

Water is definitely on your list before you go looking for property. Having more than one source is an advantage. Having no sources is a recipe for frustration.

The property here works well. There is a creek that flows all year. It supplies water for livestock out in pasture and my garden during dry times. There is a dug well with a hand pump to supply livestock water at the barn. There is a drilled well to supply the house. Rain barrels supply additional water for the garden and container plants.

We knew before we bought any property we would need water for all these things. When we looked at different properties, we checked out the water sources. If the property didn’t have water sources on it, we kept on looking. Yes, looking gets tiring and you are tempted to compromise. If you compromise on the water you need, you will regret it as long as you live there.

Creeks are nice on a property. They do bring problems with erosion – preventable with a riparian zone – and fencing as high water carries fences away.

With Great Trepidation

Deciding to try living in the country, maybe some homesteading is not an easy decision. It can be downright scary. Maybe it should be at least a little scary.

Picking out that piece of property needs to be a little scary as it is not only a big financial investment but where you will try to live this new life style. The wrong piece will doom you to unhappiness, struggle and failure. The right piece can make you wonder why you waited so long to move.

How do you know a good property from a wrong property? The next two weeks may help.

Perhaps you noticed the water flowing through the siphons slowed down as the top jar emptied out. Why would it do this?

Is this slowing related to less water in the jar so the mass is less making the water pressure on the siphon less?

When people go down to the bottom of the ocean, they go in small vehicles called bathyscaphes with very thick windows. Why is the glass so thick?

Question: What is water pressure?

Materials:

Scale

Thin plastic water bottle, empty

Water

Procedure:

Place the empty water bottle on the scale to mass it

Massing the empty bottle is important as you can then subtract this mass to find the mass of the water you add later on.

Take the bottle off the scale and pour 1 cm water in the bottle

Mass the bottle and water

Take the bottle off the scale

Pour 1 cm water in the bottle

The first centimeter is in the bottle. It distributes this mass over the bottom putting pressure on the scale.

Mass the bottle

Repeat this until the bottle is full or the scale can not have more mass on it

Observations:

Masses of bottle and water

Conclusions:

What happens to the mass of the bottle and water each time you add more water?

The bottle is filling up. Still all the mass of the water rests on the bottom of the bottle sitting on the scale.

If you were a bug standing on the bottom of the bottle, how much mass would be resting on your back when the first water landed in the bottle?

How much mass would be resting on your back when all the water is in the bottle?

Pressure is how much mass is resting on a certain area. As you add water mass to the bottle, what is happening to the water pressure on the bottom?

Water has a mass of 1 g for each cubic centimeter. If you were standing under a column of water a meter (100 cm) tall, how much mass or water pressure would be resting on you?

What if that column of water was 10 meters (1000 cm) tall?

Why are the windows of the bathyscaphes so thick?

What I Found Out:

Every time I added water to my bottle, the mass increased. Only 58.8 g of water would sit on my buggy back when the first centimeter of water arrived in my bottle. I’m glad I’m not a bug on the bottom of the bottle when the bottle was full because I would have 510.0 g of water sitting on my back.

The bottle is now full. All the mass is still resting on the bottom of the bottle giving that amount of pressure on the scale.

Since the area the water was resting on did not increase, the water column kept getting taller and heavier putting more pressure on that same area.

A column of water 100 cm tall would put 100 g of mass or pressure on my shoulder. But a column 1000 cm tall would put 1000 g of mass on my shoulder.

Bathyscaphes go to the bottom of the ocean, miles down. A mile is about 1.5 km or 1500 m or 150,000 cm which is 150,000 g or 150 kg of mass. [A kilogram is about 2.2 pounds so that is 330 pounds.] This would break a regular window. The thick glass is harder to break with the pressure.

1 ½ gallon water (Add a drop of food coloring to make it easier to see.)

Large measuring cup

Large pan or bowl to set a jar in in case the water spills

Chair or steps as high as a gallon jar

Note: It is easy to spill water in this project so working outside is a good idea.

Procedure:

Hold both ends of the tubing in one hand

Pour in water to half fill the tubing

Hold an end in each hand

Lift one end of the tubing and see what the water does (be careful not to spill)

Lower that end and lift the other end

Lower that end so the ends are even

Hold a thumb or finger over one end of the tubing

Lift one end of the tubing and observe the water

Lift the other end and observe the water

Even the ends of the tubing and block both ends with your thumbs or fingers

Lift one end of the tubing and observe the water

Lift the other end and observe the water

Fill one gallon jar almost full with water

Set the jar on the step or chair

The siphon tube is full of air when it’s put into the jars. The water can’t push the air out so no water flows through the tube.

Set the empty jar in the large pan on the floor next to the step or chair

Put the tubing into the empty jar

Pull enough tubing out to put into the jar of water all the way to the bottom

Observe what the water does

Take the tubing out of the water

Hold both ends of the tubing and pour water into it until the tubing is full

Once the air is out of the siphon tube, water runs quickly from the full jar into the empty jar.

Close off one end tightly with a thumb

Put the open end back into the empty jar

Put the closed end into the jar of water half way to the bottom

Release the end of the tubing and push it to the bottom of the jar

Observe what the water does

Especially when the full jar is on the low step, the siphon loop rises high above the jars. Yet the water still flows from the top jar into the bottom jar.

Pulling some of the tubing up from the bottom jar, make the loop between the two jars higher until the tubing only goes to the bottom of each jar

Observe what the water does

If the top jar is empty, switch the jars and start again

Put the full jar on a lower step or chair and do this again

Observe what the water does

It’s easy to see why water would move from a jar set higher than the lower jar yet water still moves from the full jar to the empty one when both are on the ground.

Put the two jars on the same level and start again

Observe what the water does

Observations:

Describe what the water in the tube does

With both ends open

With one end open

With both ends blocked

Describe what happens with the siphon tube

When put into the jars filled with air

When put in the jars filled with water

Describe what happens when the loop is lifted up

Describe how the siphon works with the jars closer together in height

When the siphon starts

When the loop is lifted

Describe what happens when the jars are beside each other

When the siphon starts

When the loop is lifted

Conclusions:

When both ends of the tubing are open, what can go in and out of the tubing besides water?

Is this still true when you block one or both ends?

How does this change how the water acts?

Why do you close one end of the filled tubing to put it into the jar of water?

Why does water move through the tubing from the full to the empty jar when it is filled with water but not when it is filled with air?

How does the movement of water change as the height of the loop changes?

Can the loop be too high for the water to keep moving?

How does the height difference between the jars affect how the water moves?

What causes the water to move from one jar to the other? Is this the same as how water comes up a straw?

Does water really move uphill by itself? Why do you think so?

The siphon continues to move water as long as the water is higher than the bottom jar until the level is so low air gets into the tube.

What I Found Out:

Making the water blue really helped me to see where the water was in the tube. I put enough in to half fill the tube.
When both ends of the tube were open, the water moved up and down as I moved the ends of the tube. The two surfaces stayed level no matter how fast or slowly I moved the tube ends.
Blocking one end of the tube changed things. The water moved only a little ways toward that end then stopped. When I lifted the blocked end up, the water didn’t move down very far until bubbles of air started moving up into that end.
Once both ends were blocked, air bubbles had to move from one end to the other to make the water levels change.
Air controls the water levels in the tube. When an end is not blocked, air can move in and out easily. Blocking one or both ends keeps the air at that level unless the open end is low enough for more air to move into the blocked end.
I used a step stool with two steps on it to set my jars on. The first time I set the full jar on the top step and the empty jar on the ground. One end of the tube went in the top jar. The other end went in the bottom jar. Nothing happened.
Leaving the two jars where they were, I took the tube out and poured water in it until it was full. Blocking one end keeps air from getting into the tube to push the water out. If the end in the lower end is open, air can bubble up into the tube before the other end gets into the top jar.
When the tube is full of air, the water doesn’t get pulled in just like when the one straw was outside the glass. A straw only works when all the air is pulled out. Having the tube full lets gravity pull the water down from the full jar to the empty jar. It works like a siphon. Raising the loop doesn’t stop the water from moving. It can slow the water down especially when the two jars were both on the ground.
The water moved differently when the top jar was placed on the different levels. Using the top step let the water move fast from the full to the empty jar. The top jar had only a little water left in it when air got into the tube and pushed the water out of the tube.
Using the lower step slowed the water down. It still moved from the top to the bottom jar, just not as fast. The top jar ended up almost empty at the end.

When both jars are on the ground, the siphon stops working when the water levels in both jars are the same leaving the tube filled with water.

Placing both jars on the ground changed everything. The water moved very slowly from the full jar to the empty one until the water level was the same in both. then it stopped. The tube was still full of water but it did not move. The water only moved when one jar had more water in it than the other, then ran downhill in a way to level it up.
Water does not move uphill on its own. It can appear to do so through the siphon loop but it is really ending up lower than at the beginning.

Do you know what a water strider is? Perhaps you’ve seen one or a group of them skating across the surface of a pond. Why don’t they sink?

Water striders prefer quiet areas of streams and ponds. They scavenge food like drowned insects floating on the water surface as the striders appear to skate their way along.

The reason water striders can walk on water is one of the special things about water. Every liquid has a place where the liquid stops and the air begins but the water surface is tough.

Question: What is special about the water surface?

Materials:

Measuring cup with 2 cups of water

Paper towels

Penny

Eye dropper

Bowl

Needle

Jar

Dish soap

Procedure:

Fold a paper towel in half and put it on the table

Put a penny in the center of the paper towel

Predict how many drops of water you think can be put onto a penny before they run off

Put 1 drop of water on the penny

A single drop of water on a penny doesn’t spread out. It holds together in a tight high half sphere because of water surface tension.

Observe and describe the shape of the drop

Use the eyedropper to put water, one drop at a time, on the penny

Remember to count how many drops of water you put on the penny

The water holds together under that water surface so tightly that even ten drops doesn’t cover the entire penny.

Stop every 10 drops to observe the shape of the water on the penny

Continue adding drops of water until the water runs off the penny onto the paper towel

Dry off the penny and set it aside

Discard the paper towel

Pour water into the bowl until it is half full

Take the needle and carefully set it flat on the surface of the water in the bowl

A needle is a flat piece of metal but it still sits on top of the water surface.

Describe the surface of the water around the needle

Take the needle out of the bowl, dry it and set it aside

Pour the water back into the measuring cup

Pour water into the jar until it is a third to half full

Describe the water surface in the jar

The meniscus is the reverse of the water drops with the lowest part in the center and the highest parts going around the edge.

Pour the water back into the measuring cup

Add 5 drops of dish soap to the water in the measuring cup

Fold a dry paper towel in half and set it on the table

Set the penny in the center of the paper towel

Predict how many drops of water will sit on the penny before it runs off

Put 1 drop of soapy water on the penny

A little soap changes the shape of a drop of water a lot as this drop on a penny shows. The water surface is no longer that high tight form but a flattened puddle.

Observe and describe the shape of the drop

Use the eye dropper to put drops of water, one at a time, on the penny

Remember to count the number of drops

Stop every ten drops and observe the shape of the water surface on the penny

Continue adding drops until the water runs off onto the paper towel

Clean up the paper towel and penny

Pour soapy water in the bowl until it is half full

Carefully place the needle flat on the surface of the water

Describe what happens

Take the needle out of the bowl

Pour the water back into the measuring cup

Pour water into the jar until it is a third to half full

Describe the water surface in the jar

Clean up

Observations:

Prediction of drops of water on a penny:

Number of drops of water you put on the penny

Descriptions of the water surface on the penny

Twenty drops of water make a penny look like a dome with the rounded water surface.

Description of the water surface around the needle

Description of water surface in the jar:

Prediction of drops of soapy water on a penny:

Number of drops of soapy water you put on the penny:

Descriptions of the soapy water surface on the penny:

Description of what happens placing a needle on soapy water:

Description of the soapy water surface in the jar

Conclusions:

What do you think the water surface is doing as the drops pile up on the penny?

Does this explain why the needle can sit on the water in the bowl?

Does this explain why a water strider can walk on water?

Why can’t a cat or dog walk on water?

In the jar water still has a small meniscus but much less than the plain water had.

Compare the meniscus or dip on the surface of the water in the jar of plain water and soapy water.

What does the soap seem to do to the water’s ability to make this surface layer?

Ten drops of plain water didn’t touch the edges of the penny but ten drops of soapy water do.

Could a water strider walk on soapy water?

What I Found Out

After setting up the penny I put one drop of water on the center. The drop didn’t spread out. It stayed in a high found half sphere.

I thought I could put 25 drops of water on the penny before it ran off onto the paper towel. This was much less than the 36 that did sit on the penny.

Ten drops later the water didn’t even touch the edge of the penny. The water stayed in the high round half sphere.

Twenty drops later the water finally touched the edges of the penny. The water was still in that high round half sphere. The water seemed to hold itself together like it had a skin on it to hold the liquid inside.

Thirty drops of water bulge upward and outward on the penny.

The half sphere kept getting higher until 30 drops of water were piled on the penny. Drop 36 finally made the water run off the penny.

My needle floated on top of the water. The surface of the water seemed to make a dip around it. It was like the skin on the surface of the water molded itself around the needle.

This water skin on the surface would hold up a water strider or other small insect. A large insect or animal like a cat would be too heavy breaking the skin and sinking.

The water in the jar was lower in the center than around the edges. The edges seemed to almost climb up the jar.

Since so many drops of water sat on the penny, I thought at least 30 drops of soapy water would sit on the penny. This was far too many as only 22 drops did.

The first drop looked a lot different sitting on the penny. The drop was more spread out and not as high.

Ten drops of soapy water didn’t quite go to the edges of the penny but took up more room than the plain water had as it was wider and not as tall.

Twenty drops of soapy water barely stay on top of the penny.

Fifteen drops of soapy water went to the edges of the penny. The next six drops made the water taller but it was flatter than the plain water. Drop 22 made the soapy water run off onto the paper towel.

When I tried to put the needle on the surface of the soapy water, it sank immediately. I dried the needle and tried again but the needle would not float on the soapy water.

The dip in the water in the jar was less. Water didn’t seem to try to climb up the sides like the plain water did.

The soap seems to stop the skin from forming on the water surface. Without that skin to stand on, a water strider would sink just like the needle did.

About Water Molecules and Surface Tension

We know now that everything is made up of atoms and molecules. Water molecules have two hydrogen atoms attached to an oxygen atom.

These three atoms don’t line up flat. Instead they form an angle with the oxygen atom at the point.

This lets the water molecules line up ≪≪≪≪<. The oxygen atom likes the hydrogen atoms near it so they hang onto each other. This is especially true at the water surface.

The surface becomes very tough, for molecules and is called surface tension. It lets the water surface curve and climb up the side of a jar a little ways. It lets insects like water striders walk on it.

Soap breaks up this lining up of water molecules. They can’t hang onto each other any more. The surface tension gets weak so even a water strider will break through.

Volume is a measure of how much stuff is in so much space. This is a special kind of space.

A line goes between two points or places. You can’t put much stuff into a line.

When you have several lines joined together, you have a shape. You can put stuff into the space between the lines but only one layer deep.

If you have a lot of the same shapes piled up on top of each other, you can put lots of stuff inside the space inside. Volume has three parts: length, width and depth.

In chemistry the basic volume has a length of 1 cm, a width of 1 cm and a depth of 1 cm. The amount of space is 1cm x 1 cm x 1 cm or 1 cm3 or 1cc [cubic centimeter].

For gases this basic measure is increased to 1 cubic meter. We can see why by comparing how water volume and air volume behave.

Question: How do water volume and air volume compare?

Materials:

1 or 2 syringes holding 12 cc to 20 cc

Note: You can probably get these from a veterinarian. You do not need needles.

Tape

10 cm length of aquarium or other soft plastic tubing that fits tightly on the syringe

Paper

Custard cup of water

Procedure:

Note: If you have only one syringe, do everything with the air, then do everything with the water.

Pull the plunger back on one syringe to the highest mark to fill it with air

Record how much air is in the syringe

Put a piece of tape over the open end and fold it around the end to seal the syringe.

Hold a finger over the tape on the end and push down on the plunger until it stops

Record the reading of air in the syringe

Put the end of the other syringe in the water and pull back on the plunger a little ways

There will be air in the syringe so turn the end straight up and push down on the plunger until the air is out

Now fill the syringe to the same mark as the air

Water is drawn up into a syringe which is sealed up. Can you push on the plunger and make the water take up less volume?

Record the amount of water in the syringe

Dry the end of the syringe and tape it closed

Hold a finger over the taped end and push down on the plunger until you can’t push it down any more

Record the amount

Push the end of the tubing onto the end of the syringe

Tape the tubing tightly onto the syringe so it will not leak

Pull the plunger back filling the syringe with air to the same mark as before

Record the amount

Make a paper plug to push into the open end of the tubing

The paper plug seems to fill the end of the tubing. It is tight, as tight as I could make it. Will it stop the air from escaping?

Note: I make this paper plug by taking a small piece of paper about 20 cm square. I push down on the center and twist the outer part around tightly to make a cone. The end of the cone is pushed into the tubing then twisted in until I can’t get any more of the plug into the tubing.

Slowly push the plunger down observing how the volume changes and the plug acts

Pull the plug out of the tubing

Put the end of the tubing into the cup of water and half fill the syringe

Hold the end of the tubing straight up and pull all the water into the syringe

Push down on the plunger enough to push all the air out

Put the tubing back in the cup of water and fill the syringe to the same mark as before

Record the amount

Make a new paper plug and push it into the end of the tubing

Note: For this last part it is a good idea to go outside or inside a shower stall.

Slowly push down on the plunger observing how the volume changes and the plug acts

Observations:

Volume of air

Starting:

Ending:

How it feels pushing the plunger down:

Volume of water

Starting:

Ending:

How it feels pushing the plunger down:

Amount of air in tubing

Starting:

Ending:

How the volume and plug act:

Amount of water in tubing

Starting:

Ending:

How the volume and plug act:

Conclusions:

Did the amount of air in the syringe change or only the volume? Why do you think so?

Did the amount of water in the syringe change? Did the water volume change? Why do you think so?

Does air have a definite, unchanging volume? Why do you think so?

Does water have a definite, unchanging volume? Why do you think so?

How does this explain the changes in height you saw in the last Project?

Tractors and other big machines have fluid filled tubes to lift buckets and other parts. Pressure is put on the fluid at one end of the tube to move things on the other end. Why do they use fluid and not air? [This is called hydraulics.]

What I Found Out:

I had one 12 cc syringe so I did everything with air first. The first step was to pull air into the syringe and tape the end.

My syringe held 10 cc of air. When I held the tape on the end and pushed the plunger, it moved quickly to start with. Then it got harder and harder to push down until it stopped. The syringe now read 3 cc.

The amount of air in the syringe stayed the same but the volume didn’t because I could push the plunger down. Air has no definite volume and can be compressed or stretched out.

Next I taped the tubing on the syringe. I held the end firmly closed and pushed down on the plunger. this time it went down to 5 cc but crept back up to 6 cc when I quit pushing down.

I made a paper plug and pushed it into the end of the tubing. I thought this was very tight but, when I pushed down on the plunger, it went down all the way as the air leaked out around the paper plug.

After taking the tubing off the syringe, I filled it with 10 cc of water and taped the end. This time, when I pushed the plunger, the plunger would not move at all. The 10 cc of water stayed 10 cc so water has a definite volume.

Since the water takes up the same volume in any container, it will have a greater depth in a narrow space and a lower height in a wide space. This is what happened in the last Project.

Next I put the tubing back on the syringe. I put water in the syringe until it read 10 cc. Holding the end of the tubing, I pushed on the plunger and it did not move as I expected.

I made another paper plug and pushed it into the end of the tubing as tightly as I could. When I pushed on the plunger a few drops of water oozed out. Then the plug shot out of the tubing and across the lab table.

Machinery uses fluid because it doesn’t change volume. When pressure is put on one end, the pressure pushes on the other end to lift a bucket or other part.

I read in “Xplor” magazine from the Missouri Department of Conservation that bugs like spiders use hydraulics to move their legs. It gives them lots of power so jumping spiders can jump long distances very quickly to catch their next meal.

If you don’t get “Xplor” – it’s free to Missouri residents – check it out on the Conservation Department website http://www.mdc.mo.gov and sign up for it and “The Conservationist.”

No matter what style of glass you pour water into, the water fits. You can pour water from a short fat glass into a tall skinny glass into a square glass. It still fits. Liquids like water are good at changing shape.

Changing shape is easy for water because it is a liquid. Water has no definite shape.

Does anything else change about water as it moves from one container to another?

Question: Does changing shape change anything else about water?

Materials:

Water

Tall skinny glass or jar

Short fat glass or jar

Square container

Scale

Ruler

Measuring cup

Procedure:

Mass the measuring cup

When measuring out water, remember it has a meniscus or dip in the surface. Water is measured to the bottom of the meniscus.

Pour 1 cup of water into the measuring cup and mass it

Mass the tall skinny glass

The problem with using this glass is how hard it is to see through it. I want to redo this project with a clear glass once I find one.

Pour the cup of water into the glass and mass it

Measure how wide the inside of the glass is in centimeters

Measure how high the water goes in the glass in centimeters

The volume of this jar will not be quite right as the bottom is not squared off. It is close.

Mass the short fat glass

Pour the water into it and mass it

Measure how wide the inside of the glass is

Measure how high the water goes in the glass

Mass the square container

When measuring any container for the inside volume, you are measuring the inside. This can be harder to do but the thick walls of this container distort the water volume results by almost 80 cc.

Pour the water into this container and mass it

Measure the sides of the container

Measure how deep the water is in the container

Pour the water into the measuring cup and mass it

Observations:

Amount of water to start:

Amount of water at the end:

Mass of water to start:

Mass of water at the end:

Analysis:

Subtract the mass of the empty container from the mass of the container of water to get the mass of water in the container.

The height of the water in the short fat jar is much lower than in the tall skinny glass.

Volume of a cylinder like a glass is the diameter times pi (3.14) times the height.

Volume of a square is the length of a side times the length of a side times the height.

The width is the diameter of the glass. Use the height of the water. Multiply to calculate the volume of water in each container.

Conclusions:

Did the height of the water change in the different containers?

Did the width of the water change in the different containers?

Compare how the height and width change.

Did the mass of the water change in the different containers?

Liquids like water change shape easily from round to square and back again.

Did the amount of water change as you poured it from one container to another?

How do you know?

What changes when water moves from one container to another?

What does not change when water moves from one container to another?

What I Found Out

I decided to measure out 250 ml of water. The water had a mass of 246 g.

When I poured the water into the tall glass, the height was 11 cm. The width was 5.4 cm so the water had a volume of 186.5 cc. The mass was still 246 g.

Glasses are slightly tapered. Jars have rounded bottoms. Square containers have rounded corners. Each affects the volume calculations a little.

When I poured the water into the fat jar, the height was only 8.1 cm. the width increased to 7.3 cm so the water had a volume of 185.7 cc.

When I poured the water into the square container, the water was 1.8 cm deep. The container was 10.6 cm by 9.5 cm so the water had a volume of 181.3 cc.

The height of the water was different in the different containers. The skinnier the container, the deeper the water was.

The mass of the water stayed almost the same. It got a little less from the beginning to the end.

The volume of the water did go down a little as I poured it into each container but stayed much the same. Each container was wet inside so some of the water did not our into the next one.

The amount of water stayed the almost the same because the mass and volume stayed almost the same. The changing shape was the only change in the water.

Chemically all water has two hydrogen atoms attached to an oxygen atom. Since this is true, all water should be the same.

If this is true, why do companies bottle so many different kinds of water? Why do some people insist on using rain water to water some of their plants?

Question: Are there really different kinds of water?

Materials:

At least three water samples from different sources

Water sources: different brands of bottled water, rain water, tap water, creek water

Collecting water samples: (bottled water is in a container) Use a glass jar with a lid. Label the jar with where the water came from.

3 glasses for each kind of water (You can use the same 3 for all the samples washing them in between but it will make the Project take much longer.)

Procedure:

Write down where each water sample came from

Label 3 glasses or custard cups for each sample

I put the number on the jar label and on the cups. The quarter cup of water half filled these plastic cups.

Put 1/4 cup water in each cup (You will have 3 glasses of each sample kind.)

Put 1 glass of each kind of water in the refrigerator for 30 minutes

Take 1 glass out of the refrigerator

Note: Do NOT taste water from any source other than bottled water or tap water.

Write down what the cold water looks and smells like

If the water is bottled or tap water, taste the water by putting a small mouthful in your mouth and swishing it back and forth.

Write down what the water tastes like.

Get the glass of the same sample sitting on the counter

Write down what this sample looks, smells and tastes like

Put the third glass of this water sample in the microwave for 10 seconds

Write down what this sample looks, smells and tastes like

Repeat this with the glasses of other water samples

You can put 1/4 cup of each sample in a saucer or glass and set it out on the counter until the water evaporates.

Write down a description of any residue left behind in the container

Observations:

Write down where each water sample came from, the ingredients listed on the bottle, what the source looked like and where it is.

Each water sample has three cups. One cup spends half an hour in the refrigerator or maybe more. One sits on the table. The other goes in the microwave for 30 seconds. I tried fifteen and the water didn’t get hot.

Describe how each water sample looks, smells and tastes –

Cold:

Warm:

Hot:

Describe any residue left if you evaporated the water samples

Conclusions:

What color is water? Why do you think so?

What does water smell like? Why do you think so?

What does water taste like? why do you think so?

If you evaporated some water, was there anything in the water? What do you think this does to the water?

Does temperature change how different kinds of water smell and taste? Why do you think this happens?

Why can some people smell the rain? What are they really smelling?

What makes different kinds of water different?

Is all pure water the same?

What I Found Out

I didn’t smell any odor for any of my water samples. None of my samples had any color. All of my water samples felt wet.

Smell and taste differed in some of the water samples. The creek water had no smell when cold, a damp, musty smell when warm and a stronger musty smell when hot.

The rain barrel sample had no odor until it got hot. Then it smelled a little like when spinach is cooking.

Bottled water always tastes strange to me. It had a slightly dusty taste when cold that became a definite odd taste when the water was warm. Hot bottled water tastes like plastic.

The well water had a slight earthy taste when it was cold. The taste got stronger as the water got warmer.

The city tap water had a metallic taste. This too was slight when cold and got stronger as the water got warmer.

All of my water samples had no color so water must have no color. I did notice the rain barrel sample had a layer of green on the bottom. The green must be algae, tiny green plants.

None of my water samples had any odor so I think water has no odor. I have smelled odors in water before but the smells were from chemicals like chlorine or sulfur in the water, not the water itself.

The taste of water seems to be like the smell of water. The water itself has no taste. When the water does have a taste, it is from something in the water.

My water samples didn’t have time to evaporate yet. I will know more in a few days.

Temperature made a difference to tastes in the water. The colder the water, the less the taste.

I can smell the rain. It isn’t really the rain I smell, it’s things getting wet like hot, dry rocks or dirt.

Different kinds of water are different if they have different things in the water. The water itself is always the same with no color, odor or taste.

Last week we found some compounds have water molecules traveling with them. How many water molecules? Not all hydrates are the same. Let’s find out about copper sulfate.

If you don’t have any copper sulfate, you can use sodium carbonate [washing soda] instead. The directions would be the same. Your answers would be different.

Before we begin you need to know some things.

One is that we will be working with an open flame. Be sure to tie hair back and keep your sleeves away.

Next please remember that a hot can and a cold can look much the same but don’t feel the same. Use the tongs for handling the can.

Question: How much water is in copper sulfate hydrate?

Materials:

Copper sulfate

Small clean empty can [cat food, tuna, no plastic coating inside]

Tongs

Scale

Stove

Procedure:

Mass the empty can

Finding the mass of the empty can is important.

Put in 5g copper sulfate

Getting exactly 5g of copper sulfate is difficult. I ended up with 4.99g.

Turn the stove on very low

Heat the copper sulfate over the flame

Shake the copper sulfate a little as it heats until all the blue color is gone

Let the can cool

Mass the can and heated copper sulfate

Observations:

Describe the copper sulfate

Mass of copper sulfate and can

Mass of can

Describe what happens to the copper sulfate as you heat it

Low gentle heat dries the hydrate without burning it or making it pop out of the can.

Mass of can and heated copper sulfate

Analysis:

Find the molar mass of copper sulfate [CuSO4]

Find the molar mass of water [H2O]

Find the mass of water in the hydrate [Subtract the final mass from the starting mass.]

Divide the mass of heated copper sulfate by the molar mass to find out how many moles of copper sulfate there are.

Divide the mass of water lost by the molar mass of water to find out how many moles of water were in the hydrate.

Compare and reduce to lowest terms the moles of copper sulfate to moles of water to find how many water molecules attach to a mole of copper sulfate. [round the proportion to whole numbers.]

Conclusions:

Why do you need to shake the copper sulfate as it heats?

Why are the molar amounts so low?

Why does this not matter finding a proportion?

Once the copper sulfate hydrate is heated until all the water is gone it is a grayish powder. The mass has dropped to 3.23g.

What I Found Out

Copper sulfate is a coarse blue powder. Looked at closely, it has an interesting crystal shape but most are broken in the powder.

When I started heating the copper sulfate, the blue got deeper and looked wet. Bits of the powder sizzled. Other bits popped and shot up from the bottom of the can. The color started changing.

As the copper sulfate heated, it clumped together. As it changed to a whiter color, the clumps broke up into powder again. Shaking the can from time to time helped it break up and heat all the hydrate.

The dry copper sulfate was 28.36g – 25.13g or 3.23g. This is .02 moles. The copper sulfate is heavy and I had only a little so the molar amount is very small.

The water was 4.99g – 3.23g or 1.76g. This is .11 moles.

The proportion is .11 moles water to .02 moles copper sulfate or 11 to 2. This would attach 5.5 molecules of water to every molecule of copper sulfate which would not happen. Why not?

Molecules can’t split up and be the same substance. A proportion compares amounts so the decimals can be moved the same number of places and keep the proportion the same.

Instead, assuming [probably correctly] that my Project had some inaccuracy in it, a proportion of 5 to 1 or 6 to 1 would be more reasonable. Copper sulfate is known to have 5 molecules of water attaching to every molecule of copper sulfate.

If you worked with sodium carbonate, I think the proportion should be 10 to 1. However I’m not certain and forgot to look it up this morning.